Multimedia messaging service (MMS) is a short messaging service launched by mobile operators, and MMS uses the wireless application protocol (WAP) as the carrier to transmit multimedia. Its most prominent feature is being able to support the multimedia function and transfer contents and information with all-round functions, and the information includes text, image, sound, video, and other information in various multimedia formats. The multimedia messaging service can achieve instant multimedia information transfer from a mobile phone to another mobile phone, from a mobile phone to the Internet, or from the Internet to a mobile phone. As compared to the traditional short message, the multimedia message is further provided with multimedia contents such as rich colorful images, sound, animation, vibration, video, etc. in addition to basic text information, and it can be further provided with application contents such as sports news with live pictures, interesting cartoons, greeting cards with rich contents, wonderful cartoon games, etc. In addition, like mails, the multimedia message can carry other types of files, such as name card holder file, etc.
With the coming of 3G era, the information carried by the multimedia message is becoming richer and richer, and thus the size of a single multimedia message becomes bigger and bigger. Currently, the size of a single multimedia message sent by many networks has increased from 100 K to 300 K, and it is estimated that it will still increase continuously in the future. Meanwhile, this brings up a problem that since the specific space on the mobile phone terminal (this specific space is protected, i.e. the user cannot access it directly) where multimedia message data is stored is limited, if the size of a single multimedia message is very large, then the number of multimedia messages which can be received and stored by the mobile phone terminal will also be very limited, and the specific space for multimedia messages will rapidly be occupied, which affects the terminal receiving multimedia messages normally; thus, the currently stored multimedia messages have to be deleted, and once deleted, they cannot be restored forever. Therefore, a solution of storing the storage of the multimedia message data on a peripheral mobile storage device (such as T card) of the terminal is proposed according to more and more demands of user, and then the storage space of multimedia messages can be broadened to the maximum extent, but this usually brings up the following technical problems, for example:
The multimedia message data is stored on a removable storage device, and since the user can directly access the storage device, it cannot get unwritable protection, i.e. the user can delete or destroy it at will. Once the multimedia message data on the mobile storage device is destroyed, many abnormal problems will occur when a multimedia message application of the terminal is started.